Connecting two charged capacitors

[Eitan Levy]

Homework Statement

One capacitor with a capacity of 6μF and another with a capacity of 12μF are charged by being connected in a series to a voltage source with an electrive force of 660V. After that, we disconnect the capacitors from the source and connect them to each other.
What is the charge and the voltage of each capacitor if we connect each positive plate to the other's positive plate?
What is the charge and the voltage of each capacitor if we connect each positive plate to the other's negative plate?

Homework Equations

Q=CV

The Attempt at a Solution

In the first case I think that the potentials will be equal, but I am still not sure how to calculate this. In the second case the charges will be equal, but again, I can't figure how to calculate it.

 

[Grands]

You wrote that the capacitor are connected in series, so to calculate the total capacity you can use the formula: 1/Ctot= (1/C1 + 1/C2)
Once you find Ctot you can use it in the Q=CV formula and calculate the charge, because you have to total voltage that is 660V.

 

[Eitan Levy]

You wrote that the capacitor are connected in series, so to calculate the total capacity you can use the formula: 1/Ctot= (1/C1 + 1/C2)
Once you find Ctot you can use it in the Q=CV formula and calculate the charge, because you have to total voltage that is 660V.

This is the part that I knew what to do in, I don't what to do after the capacitors are connected to each other in each case.

 

[epenguin]

What is the charge and the voltage of each capacitor if we connect each positive plate to the other's positive plate?
What is the charge and the voltage of each capacitor if we connect each positive plate to the other's negative plate?

. The attempt at a solution
In the first case I think that the potentials will be equal, but I am still not sure how to calculate this. In the second case the charges will be equal, but again, I can't figure how to calculate it.

I think I would not calculate anything, I would just draw a picture. What are you putting in contact with what, and what are the charges going to do?